The present invention relates to film-shaped dust collecting electrodes in a dust capturing stage in a dust collecting apparatus which forms a part of an air cleaning equipment for removing dust, smoke of cigarettes, bad smell, etc. contained in a contaminated air within a room such as a vehicle occupant compartment, especially in an air within an enclosed room upon air-conditioning or upon rainy weather, and also to an electric dust collecting apparatus constructed by making use of the film-shaped dust collecting electrodes. In more particular, it relates to improvements in an assembly of film-shaped dust collecting electrodes forming a dust capturing section in the so-called two-stage type electric dust collecting apparatus in which dust in a contaminated air is charged in a charging stage and the charged dust is captured in a dust capturing stage.
Heretofore, the above-mentioned type of film-shaped dust collecting electrodes consisted of flat film-shaped dust collecting electrodes each made of a rectangular film of insulating material such as plastics or the like having a conductive thin film coated on its one principal surface with an uncoated margin left around the conductive thin film, and similar film-shaped dust collecting electrodes associated with spacers each of which electrode has a plurality of protrusions and recesses for use as spacers formed in the uncoated margin around the conductive thin film, and these two different kinds of film-shaped dust collecting electrodes were alternately stacked in multiple on one another to form a dust capturing stage in a two stage type electric dust collecting apparatus.
Accordingly, in order to form the dust capturing stage by making use of the aforementioned film-shaped dust-collecting electrodes, two kinds of electrodes consisting of the flat film-shaped dust collecting electrodes and the similar film-shaped dust collecting electrodes associated with spacers as described above were necessitated, and so the dust capturing stage was expensive in manufacturing cost as compared to a structure made of a single kind of film-shaped dust collecting electrodes.
Moreover, in the care of alternately stacking the above-mentioned two kinds of film-shaped dust collecting electrodes on one another, since there was no means for mutually engaging adjacent electrodes with each other, the respective electrodes were liable to displace relatively to each other in the directions at right angles to the direction of stacking of the electrodes, hence mutual positioning of the respective electrodes was troublesome, and consequently the assembling work pof the dust capturing stage necessitated a lot of time and labor.